(1) Field of the Invention
The present invention relates to an electric power supply device for a slide structure, which securely prevents a long wiring harness arranged in a casing by being folded in a U-shape from being bent, coping with a long-sliding-type slide structure such as a slide door and slide seat of a motor vehicle.
(2) Description of the Related Art
FIG. 1 shows an example of a conventional electric power supply device as disclosed in Japanese Patent Application Laid-Open No. H11-342807.
An electric power supply device 61 is mounted on a slide door of a motor vehicle and includes a long casing 63 for receiving a flat wiring harness 62 by folding it in a U-shape, a flexible reinforcing plate 64 provided on an outer surface of the flat wiring harness 62, a slider 65 provided on a movable end of the flat wiring harness 62, and a rail 66 for slidably engaging with the slider 65.
The reinforcing plate 64 is made of a thin steel material and sticks to a magnetized wall 67 of the casing 63 so as to prevent the flat wiring harness 62 from hanging down. The movable end of the flat wiring harness 62 is connected to a wiring harness 68 at the slider 65, while a fixed end of the flat wiring harness 62 is connected to a wiring harness 69 on the side of the slide door.
When the slide door is opened or closed, the slider 65 moves back and forth along the rail 66, while the flat wiring harness 62 moves back and forth integrally with the slider 65 as being bent in a U-shape so as to absorb a stroke of opening and closing slide door. Thereby, electric power or electric signal is always supplied from the body-side of the vehicle to auxiliary machines of the slide door.
However, as for the conventional electric power supply device 61 as described above, since the flat wiring harness 62 is used as a wiring harness, the number of circuits or supplying current is limited. Further, since the reinforced plate 64 made of steel material is used and the wall 67 of the casing 63 is magnetized to make the reinforced plate 64 adhered to the wall 67 magnetically, causing a complicated structure and increase in cost.
Therefore, instead of the flat wiring harness 62, an electric power supply device (not shown) has been proposed, in which device a normal wiring harness having a cross section of a round shape or rectangular shape is used for preventing the wiring harness from hanging down due to its stiffness.
However, as for the electric power supply device described above, if the slide stroke is short, it works well, but on the other hand, if the slide stroke is long as seen in a case of an electric power supply device 71 for a long slide door or long slide seat of a motor vehicle as shown in FIGS. 16-18, when the slide structure such as the slide door or slide seat moves, as shown in FIG. 17, the wiring harness 72 hangs down or bends during the movement, and when the wiring harness 72 is being slid further, as shown in FIG. 18, the wiring harness 72 is folded repeatedly, causing that the wiring harness 72 can not be slid further. Here, in FIG. 16, the reference numeral 73 denotes the slider and 74 denotes the casing.